Do not use a dormant spray on beech, butternut, Colorado blue spruce, hickory, holly, sugar maple, Japanese maple, or walnut.

When to Spray

When to Spray

This combination spray can only be applied when plants are completely dormant.

Applying at the improper time can burn leaf buds that have started to swell or show any sign of green.

Apply between February and March when the temperature remains at 5°C (41°F) or above for a minimum of 24 hours.

Distribution of the spray will be more efficient on a day without wind; higher wind speeds won’t allow for the mixture to adhere to the plant.

Dormant spray will coat and dry most effectively when the forecast is clear of precipitation.

Spray early in the morning so the plant will be completely dry by evening. Do not spray if there is any chance of frost overnight.

How to Spray

How to Spray

Mix lime sulphur and horticulture oil (available together as a dormant spray kit) according to the package directions. The easiest method of application is to use a hose end that attaches to your garden hose.

Spray the plant starting at the top until it just starts to drip off the branches. If you start spraying from the bottom, you will run out of product before the job’s done.

For roses, be sure to spray the soil around the base of the plant as well to control powdery mildew and black spot.

Do not let any of the mixture fall or drift onto hard surfaces such as interlock, natural stone, brick, concrete, stucco, wood, or aluminum siding as it may leave a permanent stain. If necessary, tape a large piece of plastic to the area before spraying.